Intranasal versus intraperitoneal delivery of human umbilical cord tissue-derived cultured mesenchymal stromal cells in a murine model of neonatal lung injury.

Clinical trials investigating mesenchymal stromal cell (MSC) therapy for bronchopulmonary dysplasia have been initiated; however, the optimal delivery route and functional effects of MSC therapy in newborns remain incompletely established. We studied the morphologic and functional effects of intranasal versus i.p. MSC administration in a rodent model of neonatal lung injury. Cultured human cord tissue MSCs (0.1, 0.5, or 1 × 10(6) cell per pup) were given intranasally or i.p. to newborn severe combined immunodeficiency-beige mice exposed to 90% O2 from birth; sham controls received an equal volume of phosphate-buffered saline. Lung mechanics, engraftment, lung growth, and alveolarization were evaluated 8 weeks after transplantation. High-dose i.p. MSC administration to newborn mice exposed to 90% O2 resulted in the restoration of normal lung compliance, elastance, and pressure-volume loops (tissue recoil). Histologically, high-dose i.p. MSC administration was associated with alveolar septal widening, suggestive of interstitial matrix modification. Intranasal MSC or lower-dose i.p. administration had no significant effects on lung function or alveolar remodeling. Pulmonary engraftment was rare in all the groups. These findings suggest that high-dose systemic administration of human cultured MSCs can restore normal compliance in neonatally injured lungs, possibly by paracrine modulation of the interstitial matrix. Intranasal delivery had no obvious pulmonary effects.